I OFFER BLACK OPAL MATRIX STONES, SLAB. MANAGEMENT CONSULTING INCLUDING MONTE CARLO SIMULATION.STONES ARE POLISHED DOWN TO 15 MICRONS. THEY ARE NOT DYED. IF YOU WANT THEM DYED, ASK. STONES IN BRIGHTNESS FROM 1 (JUST BLACK) TO 5 FIRE CAN BE SEEN IN VERY LITTLE LIGHT (FULL MOON).